"If it takes two doses to get rid of this pandemic, we will find a way to put them."

Israeli doctor Tal Zaks, in an image supplied by his company.

It is often said that the coronavirus plague caught humanity off guard, but it is a lie. The first cases of rare pneumonia in China were known in late December. On January 11, Chinese scientists published the genome of the culprit: a hitherto unknown coronavirus. Just two days later, on January 13, the US company Moderna and the US National Institutes of Health completed the design of an experimental vaccine and began manufacturing it. On March 16, in a record time of 63 days, a volunteer was given the first vaccination. Israeli doctor Tal Zaks, born in Haifa in 1965, is one of those responsible for this unprecedented record. Its experimental vaccine against covid is one of the most advanced and is already being tested in an international trial with 30,000 people. The first data in adults over 55 years of age, even in septuagenarians, are promising. "I am very happy with the results we have had in older people, because a month ago I became one of them," jokes Zaks, Moderna's scientific director, in a videoconference from the American city of Cambridge.

Question. Your vaccine would require two doses.

Reply. Yes, we believe that a second dose clearly stimulates the immune response. If you can, you want to give a push. Can one dose be enough? May. We decided to try two doses because, given the severity of this pandemic, we do not want to take risks. I don't want to do something that's only half as good. I want to offer the greatest possible protection. And this is achieved with a second dose.

Q. What are the implications of needing two doses? If with one dose it is already a great challenge to vaccinate almost the entire world population, two doses is unprecedented.

R. It is true that, from an operational point of view, it is more complicated. And it is true that it will require more resources. But do we want a vaccine that is very effective or a vaccine that is effective? I want to offer the best possible vaccine. And I think the situation with the covid justifies the logistical challenge of giving people two doses. If two injections are needed to get rid of this pandemic, we will find a way to give two injections.

Q. What can go wrong during the current phase 3 trial [the final trial, with 30,000 people]?

A. What worries me most is that not enough people get infected and have the disease during the trial. It is great for society that the [epidemiological] situation is under control and the virus disappears, but the ability of phase 3 to demonstrate the efficacy of the vaccine depends on having more cases in the control group, whose members receive a placebo, than in the group of vaccinated people. If there are no cases, we will not know if the vaccine is effective.

"If there are no infections, we will not know if the vaccine is effective"

Q. What are the risks of starting people vaccinated too early? It seems that Donald Trump would want to start vaccinating before the presidential election on November 3.

R. I'm not going to talk about politics [laughs]. I believe that it is important for us and for society to understand the safety profile and adverse events well before starting to vaccinate. We are doing a large clinical trial, with a control group receiving a placebo. If we see events related to safety, we will know if they occur with the same frequency in the placebo group and in the vaccinated group. If we start giving people the vaccine, we must know that no vaccine is 100% effective. Some people will get sick despite my vaccination. How do I know that these people have not gotten worse from my vaccine? People can start to say, “Oh my God, they gave me your vaccine and I am sick. Your vaccine has made me sick ”. This is not scientific, but we need data to be able to explain it. As promoters of the trial, we want to ensure that we have data confirming the efficacy and safety of this vaccine before we begin the vaccination campaign.

P. There is a logical rush to have vaccines.

A. I think there is a legitimate public debate about when you have enough information to justify the risk. Even if we wait until the end of the year or until the beginning of 2021 to have more information about the trials, we will still have limited data and we will still not know what we do not know. There may be long-term adverse events. From what point is the risk that people continue to die despite the fact that they could be vaccinated justified? It's a very difficult debate about risk and benefit. The more data we have, the better: at the government level, because in the end the government of each country will have to decide whether to compensate the risk / benefit, but not only at the government level. It is also an individual choice. I don't think anyone is going to impose mandatory vaccinations. Each person, to want to be vaccinated, will have to be sure that the vaccine is sufficiently safe and probably effective. So it is important to have this data, so that people can make an informed decision for themselves. And so that governments can make informed decisions for their citizens.

“No vaccine is 100% effective. Some people will get sick despite my vaccination "

Q. The British pharmaceutical AstraZeneca has assured that it will produce the Oxford University vaccine at cost. Why is Moderna's vaccine going to be more expensive than other vaccines?

A. I think, to be fair, the price has to reflect the value of this vaccine to some extent. I think that the price we ask, with the value it has, is more than reasonable with respect to the investment we have made. The price is less than that of a diagnostic test. And, every time you are sick, you need to take a diagnostic test. With a vaccine, you should be protected for a long time. So if we think about the value to society ... Maybe other companies can offer their vaccines for free - it's their choice and maybe they can afford it. But I don't think we should be expected to do this. And honestly, I don't think it's fair, given the investment that this vaccine has made possible.

Q. How long will immunity last?

A. People often ask me how long the protection will last. And the answer is: I don't know, but obviously the higher the amount of antibodies [generated by the vaccine] that you start with, the more likely it is to work and the more likely it is to last longer. We must at least reach levels similar to those of people who have overcome the disease, but if we can reach higher levels, we hope it will be better. We choose higher doses of vaccine because we believe that our platform allows us to do it in a safe and tolerable way.

Q. You and other executives at Moderna have sold millions of dollars worth of shares in your company in recent months. Why have you sold shares, if the vaccine is supposed to work and you would earn more by selling later?

R. It is very simple. I answer the same thing I answered my wife: I cannot sell stocks based on whether the vaccine works or not. That is illegal, it is inside information. I can only sell shares if I prepare a predetermined sale plan before I know anything [conditions are set for automatic sale if the share price reaches a certain level]. When I prepared my plan, we had not yet injected anyone with the vaccine. I did not know anything. What I knew is that I have been working with the company for five years, I had a little money [accumulated in stocks] and I needed to diversify what I had. Looking back, I don't know if I was stupid, but I can't change it.

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Avoiding covid is not enough

One of the great enigmas is whether the current experimental vaccines will be able to stop the pandemic. A vaccine can prevent the disease, covid, but not prevent asymptomatic infections. Will a person immunized with Moderna's vaccine be able to transmit the virus to other people if they become infected? "We do not know. And it will be very difficult to know ”, admits doctor Tal Zaks. Moderna's scientific director recalls that a team of Hong Kong researchers has just discovered the alleged first case of reinfection by the coronavirus: a 33-year-old patient who had a first infection with very mild symptoms and a second asymptomatic four months later. Zaks believes that virus detection methods are so sensitive that it is difficult to interpret these cases. “If I am already immune to the virus, but someone infected sneezes on me, the virus will be in my nose. If you arrive five minutes later and put a cotton swab up my nose, you will see the virus. Does that mean I'm sick? No. Does it mean that I can transmit the virus to another person in those five minutes? It can, who knows ”.